1. Field of the Invention
The present invention relates to a flow control valve, and more particularly, to a flow control valve that may reduce a weight of a valve and may maintain a constant flow rate at all times regardless of a sudden pressure change in an inlet and an outlet of the valve.
2. Description of the Related Art
Generally, a flow control valve may be used for many industries such as a nuclear power plant, a thermal power plant, a ship, an airplane, a rocket engine, and the like.
A liquid propellant rocket denotes an aviation device that may mix a liquid fuel and an oxidizer, burn the mixture in a combustion chamber, discharge an exhaust gas through a nozzle, and thereby obtain a propulsive force due to an action-and-counteraction principle. The liquid propellant rocket may easily control the propulsive force using valves and pumps. Due to this aspect, the liquid propellant rocket is more popular than a solid propellant rocket. To adjust the propulsive force of the liquid type rocket, there is a need to regulate a flow rate of the fuel and the oxidizer supplied to the combustion chamber. For this, a flow control valve may be required.
When the flow control valve is used for ground systems and the like, an increase in weight may not become an issue. However, when the flow control valve is used for a ship, an airplane, a rocket, and the like, fuel efficiency may deteriorate as the flow control valve becomes heavier. Accordingly, the lighter the flow control valve, the better.
In a conventional art, a poppet valve is generally used for the flow control valve. The poppet valve may install a poppet member to perform a reciprocal motion in a flow passage of the valve, and thereby may control a valve opening while selectively opening or closing the flow passage according to a movement of the poppet member.
Specifically, the flow control valve according to the conventional art may control the poppet member to vertically move with respect to a flow direction of fluid and thereby may regulate an area of the flow passage of the valve to control a flow rate of the fluid.
However, when upwardly and downwardly moving the poppet member, the conventional flow control valve needs a great amount of force due to a flow induced force acting on the poppet member. Thus, an actuator may need to be increased in size.
Also, a drive force for the actuator may need to be increased due to the flow induced force on the poppet member. Accordingly, a configuration of the actuator may become more complex and heavier. In addition, the actuator may not be readily controlled and may easily malfunction.
Also, when an abnormal and sudden pressure change occurs in an inlet or an outlet of the flow control valve due to a disturbance, it may cause a radical change in a flow rate, which may result in endangering the stability of a system.